Thursday, January 17, 2008

There are 100 prisoners each with a unique name. There are 100 boxes, each one containing a single prisoner's name such that every name is in exactly one box. Each prisoner has to select and open up to 50 boxes and if his name is not in any of these 50 boxes then all the prisoners are executed. They go through this process one at a time, each prisoner finishing before the next begins. They can communicate to come up with a strategy before beginning, however, they cannot communicate in any way after the process has begun.

What is the best strategy that results in the prisoners' greatest chance of survival? Hint: It is greater than 30%. And if that's too easy, prove that this is the optimal strategy.

Wednesday, January 9, 2008

Who would have thought that leaving South Africa for the US would result in yet more bandwidth woes! Why yes, it's true...I've hit the "cap". I just got a call from Comcast this morning saying that I exceeded the limit last month and that I was being given a warning.

Let me get one thing straight first. The cable here is *far* better than the ADSL back in SA. Don't get me wrong there. However, they could be a little more upfront about their restrictions. Apparently I was in the top 0.1% of their bandwidth users last month. All I was told that if I return to this top 0.1% bracket again within the next year then my account will be suspended for a year. Wow, that's quite harsh don't you think? Especially when you consider that no-one can ever know what that limit is in terms of an actual bandwidth figure and that as much as a tried the guy refused to even give me a ball-park figure. All he said was that I had to "drastically reduce" my usage and that if he gave me a figure he would be fired.

I was rather surprised at how interrogating he was. Some of the questions I can understand, such as asking if I had a wireless network and whether or not it was secure. When he asked what I was doing that was causing such excessive usage -- man, I got a little annoyed. I told him straight that it was private. What are they going to benefit knowing what I use my line for?

The good thing is they have plenty DSL providers here. Hopefully they'll be more customer-friendly. Yes, they charge a bit more, but the other stories I've read about Comcast are a little saddening (even though they don't come close to the evilness of Telkom!) such as sending forged TCP RST packets and throttling encrypted traffic.